From the Nuclear Pore Complex to Smart Artificial Nanochannels

When two reservoirs limit their connection to narrow channels with nanoscale cross-sectional size, designing these nanochannels provides a great opportunity to check, select and manipulate the molecules in transport. The proposed work aims to guide the rational design of smart nanochannels with functional gating structures and sensitive response to external stimuli. We will explore the paradigm-shifting idea of utilizing sequence-controlled polymer as coating materials to build programmable artificial nanochannels. Seeking bioinspiration, we will continue our previous research effort to understand the mysterious structure and debated transport mechanism of the nuclear pore complex (NPC). As the most immense and complicated biological nanopore that exists in nature, NPC provides a perfect example of self-assembling sequenced polymers (unfolded proteins) into a selective and efficient nanogate. We will learn from the NPC how to achieve exquisite control and high efficacy of molecular transport towards biological level, and how to encode the gating function into the sequences of the coating polymers. We will also study the microphase-separation of end-tethered polymers in bad solvent for surface-patterning design. The ultimate goal that interlinks the proposed research thrusts is to understand the intricate coupling between molecular conformations, electrostatics, hydrophobicity, steric interaction and acid-base equilibrium in nanoconfined geometry. We have developed theoretical tools to account for these coupled interactions with molecular details and will make them a platform method to examine the sequence-structure-function relation of the functional polymers. Our theoretical approach will provide design principles that are urgently needed to reduce the high-dimensional design space of the nanochannels, and to enable the inverse design for personalized functions. The proposed work is of fundamental importance in life science and nanotechnologies with potential impacts for an assortment of applications including but not limited to desalination, molecular filtering, biosensing, drug delivery, energy conversion and nanofluidics.